The present invention relates to a distributed processing system which operate, on an on-line basis, to transfer programs among processors that are connected through a network, and particularly to a processing method for each of the processors to relocate programs among computers depending on the program organization.
Conventional distributed systems including a plurality of processors connected through a network are designed to introduce programs to each processor on the basis of a predetermined program loading schedule. In such cases where the occurrence of abnormality in a processor or a program to be introduced has been newly created, as described in JP-A-62-115556, for example, however, such system do not have the concept of allowing each processor to determine a program to be introduced and executed depending on its own situation.
The above-mentioned prior art does not consider unexpected changes in the system organization, and programs to be introduced and executed by each processor are determined in advance and registered. On this account, upon the occurrence of a change accompanied by a failure, recovery, maintenance activity and system expansion, it is necessary for each processor to register again programs to be introduced before executing all necessary programs. This alteration of registration is a change of system design parameters imposed on a running processor, and therefore it is difficult to achieve on-line implementation. If the alteration of registration involves the transfer of a program in execution among computers, it is inevitable to halt the program execution.
Accordingly, in order for each processor to change a program to be introduced and change the program allocation, the system must be halted temporarily, resulting in a lack of flexibility in dealing with a change in the system organization.